Liberty University switched abruptly to virtual classes beginning Monday — just a week after they began — because of a spike in coronavirus cases.

The decision to temporarily pause indoor events, teach online and ramp up other safety measures was not taken lightly, according to a university announcement Friday. “The campus infection rate is higher than at anytime last year, our only local hospital is reaching capacity for ICU COVID treatment, and we project our Annex quarantine capacity to be reached soon,” school officials wrote.

On Aug. 15, the campus reported just three positive cases, according to the school’s online dashboard. By Aug. 24, that number among students had spiked to 124. There are an additional 35 cases among the faculty and staff.

Nearly 500 people had been asked to quarantine. The dashboard, last updated Wednesday, reported 274 students on the Lynchburg, Va., campus in quarantine and an additional 111 commuter students and 107 employees in quarantine.

Colleges across the country are starting classes this month with varying levels of restrictions and efforts to limit the spread of the coronavirus. With vaccines widely available, many have resumed in-person classes and traditions that had been disrupted by the pandemic. But the surging delta variant has left some schools scrambling to rethink their plans.

And as data has come in from testing on some campuses, a few have pivoted.

Duke University in North Carolina announced changes Monday afternoon, requiring masks indoors and outdoors on campus in most circumstances, allowing faculty members to teach virtually for the next two weeks, suspending group indoor dining and setting up tents to provide students meals to go. New limits on student activities will be put in place, according to an email to campus from university leaders. And they reminded faculty and staff members that vaccinations have been made a condition of employment.

At Duke, which is administering more than 20,000 tests weekly, 364 people tested positive in the past week — a positivity rate of 1.59 percent, according to the university’s coronavirus dashboard. The vast majority of those new cases were students.

Ninety-eight percent of Duke’s student body is fully vaccinated.

Rice University announced earlier this month that it would hold classes online for the first two weeks of class after testing indicated higher-than-expected numbers of cases among vaccinated people. Some of that testing was later found to be flawed. But remote instruction will continue at the Houston school at least through the end of this week, university spokesman Jeff Falk said in an email Monday. “At this point, no decision has been made beyond that,” he said.

Virginia’s Liberty is a school with national influence, an evangelical university that has been a touchstone for Christian and conservative politicians. In March, Liberty President Jerry Prevo announced “joyful news: Liberty plans for a return to normal operation, as things were pre-pandemic.”

He said health and safety would remain a primary concern.

The school does not require students and employees to be vaccinated or to wear masks on campus.

The school had been hosting indoor and outdoor events to welcome students back but announced last week that it would pause indoor events and in-person classes until Sept. 10.

On social media, some questioned whether the university’s large events held this month had driven the spread.

At another recent event, for the university’s College of Osteopathic Medicine, students were wearing masks and were spaced apart in the venue.

The school has not changed plans for its home football game Saturday. The school’s Williams Stadium can hold 25,000 people.

But convocations and campus worship services typically held indoors will move to the stadium temporarily, school officials announced last week.

Students not in isolation because of positive test results or in quarantine because of close contacts who tested positive are free to move about the campus, school officials wrote. “We do encourage social hygiene practices that will help reduce the spread of disease, including washing your hands, some physical distancing outside your circle while outside, and even wearing a mask in indoor circumstances where it could help,” they wrote.

School officials said vaccination clinics would be offered on campus soon.

Scott Lamb, a spokesman for the university, did not immediately respond to a request for comment Monday.

Keith Anderson, executive director of Liberty’s Student Health Center and Wellness Initiatives, said in a written statement to the university community: “We are taking the necessary steps and actions to lighten the burden to our medical service providers, the local hospital resources, and to do our part to keep our community safe,” adding, “We understand the severity of the pandemic and desire to act swiftly to ensure the health and safety of our campus.”